ANTARCTIC CIRCLE • DICCIONARIO INGLES.COM • Definition of Antarctic Circle

... of a "southern land" was not confirmed until the early 1820s when British and American commercial operators and British and Russian national expeditions began exploring the Antarctic Peninsula region and other areas south of the Antarctic Circle. Not until 1840 was it established that Antarctica was indeed a continent and not just a group of islands. Several exploration "firsts" were achieved in the early 20th century. Following World War II, there was ...

— The 2008 CIA World Factbook • United States. Central Intelligence Agency.